Diagnosing Bowel Cancer

If you are worried about your health you should visit your doctor immediately. Your doctor will ask you some general health questions and will quite possibly examine your back passage (rectum).

They do this by putting a gloved finger into your back passage (rectum) and feeling for any lumps or swellings. The examination may be uncomfortable but should not be painful.

Blood tests may be ordered to check for anaemia (which is common among bowel cancer sufferers but can also be caused by other factors), and will see if your liver and kidneys are functioning normally.

X-Rays You may then be referred to the hospital to see a specialist doctor or nurse for further tests and possible X-Rays.


The specialist may want to perform a sigmoidoscopy, which uses a small tube with a camera in it to look inside the back passage and the lower part of your bowel. This tube also pumps a small amount of air into the bowel to inflate it slightly so the doctor or nurse can see the bowel more clearly.

The doctor or nurse will take samples at the same time if they see any abnormalities or polyps of the bowel lining and send them away to be examined. This whole procedure shouldn’t take any longer than about 15 minutes and you can go home immediately after.

Don’t be alarmed if you have a little bleeding from the back passage after especially if you have had polyps removed. This is normal and will clear up after a few days. You will be required to have an enema beforehand to ensure your bowel is empty.


Colonoscopy is classed as the "Gold Standard" here in New Zealand. If you are required to have a colonoscopy, which looks at the whole bowel, the procedure will be similar to the sigmoidoscopy and can take up to an hour.

You will probably have a sedative before this test to make you drowsy as it would be uncomfortable without it. The doctor or nurse will examine the lining of the whole length of the bowel and take samples if necessary.

You may have to wait a couple of hours after the test before you can go home so it is best to have someone to take you home afterwards. Sometimes this procedure is covered privately through some Insurance companies in New Zealand such as Southern Cross Healthcare with certain policies.

This will save you time on the waiting list here in New Zealand which takes far too long. In some instances, patients have to meet certain criteria to be eligible for publically funded colonoscopies (I.e. first-degree relative that has had bowel Cancer).

It always pays to check with your health insurer what procedures can be covered by your chosen policy.

CT Colonography/Virtual Colonoscopy

CT colonography (CTC or CAT scan) is able to scan the entire abdomen and pelvis searching for polyps or cancers in the bowel.The extent and type of bowel preparation depend on the patient's age and condition but ideally, the entire colon should be cleared usually with laxatives.

You will be asked to remove all of your clothing and will be given a gown to wear. You will then be taken to the CT scanning room.

Carbon dioxide gas will be introduced into your bowel so that the surfaces are clearly outlined. To achieve this the radiographer will gently introduce the gas through a small tube passed into your bottom. It is the same gas that is used to make soda water, and it is extremely safe to use.

Two scans will then be performed: one scan with you lying on your back, and the other lying on your tummy. Each scan takes only a few seconds. Afterwards, there will be some gas in your bowel and you may feel a little uncomfortable and bloated. However, your body will absorb the gas very quickly so the discomfort should disappear by the time you leave the department.

There may be some fluid or residue still in your bowel so do not stray from the access to a toilet. You may eat and drink normally immediately after the examination. The radiologist will study your images and the report will be sent to your doctor.

Barium Enema

Sometimes a Barium enema is required which is an X-ray of the large bowel. Barium is a white liquid which is mixed with water and passed into your back passage (rectum). You will need to hold this liquid in the rectum while the X-rays are being taken.

This liquid easily shows up any lumps or swellings on an X-ray. You will be required to have an enema beforehand to ensure your bowel is empty and will need someone to take you home afterwards.

You may be constipated for a few days after the test and your first couple of stools will be white until you have passed the barium out of your system.

Charity Achievements

Key Milestones reached by Bowel Cancer Foundation Trust team.


Dollars distributed to help fund vital research and providing better patient outcomes


Bowel cancer survivors rehabilitated after gruelling treatment helping to reduce cancer re-occurrence


Bowel screening kits provided to Kiwi’s who do not qualify for free public screening to detect bowel cancer early


Loving families kept together for longer with help for immunotherapy treatments that help reduce tumours